The present invention relates to an apparatus for recording pattern information for control of the operation of a flat knitting machine, which is employed to write on a recording medium such information in the form of pattern data and/or control data for each knitting course of a carriage.
U.S. Pat. No. 4,214,460 discloses a flat knitting machine having an electromechanical needle selecting mechanism which is such that pattern information for knitting, previously recorded in a recording medium, e.g. paper tape, is read by a reader in a controller unit attached to the knitting machine and is then stored in a computer means in the controller unit. Needle selection and other relevant functions of the machine for each knitting course can thus be electro-mechanically controlled by the controller unit according to the pattern information stored in the computer means.
With such flat knitting machine it is a usual practice that pattern information for each knitting course is recorded by punching the recording medium or paper tape and is then input into the computer means in the controller unit by having the punched paper tape read by the reader.
Now, a V-bed flat knitting machine, unlike a single-bed flat knitting machine or circular knitting machine, has a pair of needle beds, front and back. With such knitting machine, not only is it possible to produce varieties of knit patterns by selectively causing the needles to knit, tuck or miss during the movement of the carriage, but also it is possible to fashion further varieties of knit patterns by transferring loops between the beds and racking one of the beds before or after loop transferring during carriage movement. Where a V-bed flat knitting machine is employed, therefore, it is necessary to input into the computer means such pattern information as which stitch or stitches hanging on which needle or needles are to be transferred in which knitting course of the carriage, and how many pitches and in which direction one of the beds is to be racked before or after such loop transfer, as well as other pattern information.
In the case of a knit pattern consisting simply of a combination of knit, tuck and miss, which can be mechanically produced on a single-bed flat knitting machine, one course of stitches in the knit fabric corresponds to one knitting course of the carriage, and therefore, necessary pattern information for knitting one course of stitches can be plotted on a square-ruled mark sheet, with one stitch shown in one grid. That is, pieces of pattern information for the course direction of a fabric to be knit are plotted on X coordinate axis on the mark sheet and pieces of pattern information for the wale direction of the fabric are plotted on Y coordinate axis, whereby a final knit pattern of the fabric to be knitted can be easily envisaged. The mark sheet having such plottings made thereon provides data as to which needles should be in the operative zone of a cam or cams during the movement of the carriage for each knitting course, since each course of stitches shown on the mark sheet corresponds to one knitting course of the carriage.
Therefore, from such mark sheet and by using reader means for optically reading the pattern information present on the mark sheet for conversion into electric signals and a paper-tape puncher for punching a tape with pattern signal holes according to the electric signals from the reader means it is readily possible to prepare a pattern tape punched with holes representing pattern data for each knitting course.
However, in the case of a knitting pattern involving a loop transfer in a particular knitting course and needle-bed racking before or after the loop transfer, the situation is not so simple, because several courses of carriage movement are required in order to obtain the desired pattern for the particular one course. For example, if one on the righthand side of two front stitches located in side-by-side relation on two adjacent needles in the front needle bed is to be placed on the lefthand-side stitch in overlapping relation, it is necessary to transfer the righthand-side stitch onto a needle opposite thereto in the back needle bed and rack the back bed one pitch leftward, and then to transfer the stitch from the back-bed needle to the front-bed needle. After the righthand stitch is thus placed on the lefthand stitch in overlapping relation, the back bed must be racked one pitch rightward. In order to prepare from a mark sheet a pattern tape punched with holes representing such racked-pattern information, therefore, the mark sheet must carry pattern information for several knitting courses of the carriage as obtained by analyzing pattern information for one course of stitches in the fabric to be knit.
That is, when writing racked-pattern or other complicated pattern information manually on the mark sheet, the operater must first thoroughly understand the sequence of operation of various parts of the V-bed flat knitting machine and then analyze necessary pattern data for one course of stitches and control data for knitting and transfer locks and needles into data for several courses of carriage movement involved while envisaging the pattern and control datas. Conventionally, therefore, the work of writing such information on the mark sheet requires a high degree of skill and considerable trouble.
The fact that where racked pattern or the like is involved, pattern information for each individual course of stitches must be analyzed into pattern data for a number of knitting courses of the carriage, partially and randomly, as above stated, poses another problem with the prior-art method of encoding pattern information for V-bed flat knitting machine operation. Although such pattern information written on the mark sheet in aforesaid manner comprises pieces of wale-directional pattern information and of course-directional pattern information as shown along X and Y coordinate axes, the analyzed information is so complicated that even a skilled operator could not evisage a final pattern from the mark sheet. As such, it is extremely difficult to check to see that the pattern information on the mark sheet is right and/or to correct errors thereon, if any.
Another problem is that pattern information shown on the mark sheet in manner as aforesaid is limited to pattern data for individual knitting courses of the carriage, e.g. which needle or needles are to be controlled to the operative position of the knitting lock or transfer lock and in which knitting course; such pattern information does not include control data for individual knitting courses, e.g. data as to whether or not the knitting lock and/or transfer lock are to be controlled to the operative position thereof relative to needles in a particular knitting course, or as to which needle bed, front or back, are to be racked rightward or leftward before or after a particular knitting course.
In the prior-art recording method for pattern information, therefore, a program sheet on which various control items for the carriage are shown correspondingly to the arrangement of tape puncher keys is employed, separately from the aforesaid mark sheet, to provide such control data necessary for the control of knitting operation for each individual knitting course. That is, control data for each knitting course, developed in manner as above described, is written on the program sheet; and according to each relevant entry on the program sheet, such control data for each knitting course is key input into the tape puncher for preparation of a control tape. As is the case with the writing of pattern data onto the mark sheet, the work of entering control data for each knitting course manually onto the program sheet requires a high degree of skill and considerable labor. Likewise, key entry of control items into the tape puncher takes much trouble.